Door latch including a permanent magnet and a latching electromagnet



Aprll 4, 1967 K. REMHOF 3,312,492

DOORVLATCH INCLUDING A PERMANENT MAGNET AND A LATCHING ELECTROMAGNET Filed April 8, 1965 2 Sheets-,Sheet 1 K. REMI-IOP DOOR LATCH INCLUDING A PERMANENT MAGNET AND April l4f, 1967 A LATCHING ELECTROMAGNET 2 Sheets-Sheet 2 .Filed April a, 1965 FIG. 5.

Attorney Uited States PatentO l 3,312,492 D001?. LATCH INCLUDING A PERMANENT MAG NET AND A LATCHING ELECTROMAGNE'I Kurt Remhof, Schalirsmuhle, Germany, assignor to Albrecht `Iung elektrotechniche Fabrik, Schalksmuhle,

Germany Filed Apr. 8, 1965, Ser. No. 446,747 Claims priority, application Germany, Apr. 9, 1964, .I 12,582; Apr. 11, 1964, .l 25,640 7 Claims. (Cl. 292-201) This invention is concerned with latching mechanisms, and more particularly with such mechanisms for use on doors such as, for instance, doors of dwellings, or cabinet or closet doors.

It is one object of this invention to provide new and improved latching mechan-isms for the aforementioned description. v

Another object of this invention is to provide integral dual 'action latching mechanisms capable of holding a door closed by the magnetic attraction of a permanent magnet and an armature for the latter, and also capable of locking a door by positive action.

Another object of this invention is to provide a dual action latching mechanism of the aforementioned description including parts operative to 4perform either of both of the two functions of the composite device.

Another object of this invention is to provide a dual action latching mechanism` of the aforementioned description involving a minimum of bulk, being adapted to be operated remotely by an electromagnety or solenoid, requiring Va minimum of bulk, and the constituent parts of which are positioned in such a way that they can be accommodated in a small substantially prismatic housing having approximately the thickness of that of a door.

Another object of this invention is to provide a latching mechanism of the aforementioned description which does not exceed the dimensions of a conventional lock that would be used for locking the particular kind of door for which the latching mechanism is intended.

Still another object of this invention is to provide a latching mechanism of the aforementioned description having a considerable mechanical strength, yet having space requirements not exceeding 'a prismatic space having a height of about 2.6 inches, `a width of about 2 inches and a thickness of about l inch.

Other objects of the invention and advantages thereof will be better understood from the following description and the accompanying drawings showing two preferred embodiments of the invention, and wherein;

FIG. l is a front elevation of 'a cabinet made of wood and having a plurality of compartments each closed 4by an individual door. FIG. 1 showing one of the compartments as being associated with a latching mechanism embodying the present invention;

FIG. 2 is a side elevation of th'at portion of the latching mechanism of FIG. l which is built into the cabinet body of FIG. 1;

FIG. 3 is a side elevation of the portion of the latching mechanism of FIG. l which is built into the door of the structure of FIG. 1 rather than into the cabinet body thereof;

FIG. 4 is a front view of the structure of FIG. 2;

FIG. 5 is a front view of that portion of a latching mechanism embodying this invention intended for use on sliding doors rather than on hinged doors which is intended to be fastened to the sliding doors;

FIG. 6 is a side elevation of the structure of FIG. 6;

FIG. 7 is a side elevation of that portion of the latching mechanism for sliding doors intended to be fastened to the fixed frame of the door and to cooperate with the portion of the structure illustrated in FIGS. 5 and 6;

FIG. 8 is a section of the structure shown in FIGS. 5

- dition when its armature 15 is not attracted to the upper "ice and 6 showing on a considerably larger scale the parts which are arranged inside of the structure of FIGS. 5 and 6, FIG. 8 being taken along 8 8 of FIG. 9; and

FIG. 9 is a side elevation of the structure of FIGS. 5 and 6 as seen when separating the two constituent shells of that structure.

Referring now to the drawings, and more particularly to FIGS. 1-4 thereof, reference numeral 1 has been applied to generally indicate a cabinet having six compartments 2. Each of the six compartments 2 may be closed by a door 3. The latch mechanism for each door 3 comprises two cooperating units generally designated by the reference characters L1, L2. Unit L1 is secured by means of wood screws 6 to the corner formed by horizontal board 4 and vertical board 5.- Unit L2 is secured by wood screws 9 to the corner of one of the doors 3 which is juxtaposed in the closed position of that door to the corner formed by boards 4 and 5.

Unit L1 comprises two complementary shells 10, 11 arranged in abutting relation (see FIG. 4) and jointly forming a housing enclosing a substantially prismatic space. Housing 19, 11 has a pair of relatively w-ide parallel outer surfaces positioned at right angles to the plane of the paper on which FIGS. 1 and 4 are drawn. Housing 10, 11 further comprises a pair of relatively narrow outer surfaces positioned at right angles to the aforementioned relatively wide outer surfaces. One of said relatively n'arrow surfaces defines a pair of superimposed passageways 17 and 17a, each between the space enclosed by shells 10, 11 and the exterior thereof. A pair of hollow rivets 12 project transversely through t-he relatively wide surfaces of housing 1t), 11, integrating its constituent shells 10, 11 into 'a structural unit. Each of the two hollow rivets 12 defines a cylindrical duct having a suiciently large inner diameter to allow the passage of wood screws 6 through the aforementioned relatively wide outer surfaces of housing 11, 11. Wood screws 6 extend beyond housing 10, 11 and secure the latter to the vertical board 5 of cabinet 1. Reference numeral 13 has been 'applied toV indicate a permanent bar magnet arranged inside f the prismatic space defined by shells 10l and 11. Permanent bar magnet 13 projects with one end thereof into passageway 17 Iand has a pole surface 13a substantially flush with the relatively narrow outer end surface of housing 10, 11 shown to the right of FIG. 2. Fixed armature plate 8 secured by wood screws 9 to door 3 cooperates with permanent magnet 13 in keeping door 3 closed, when closed. This is effected by magnetic attraction between permanent magnet 13 and armature plate 8. Armature plate 8 forms a support for a hook-shaped latch 7 projecting from the surface of armature plate 8 and forming jointly with armature plate 8 the latch unit which has been generally designated by the refrence character L2. Movable latch 16 inside of Ihousing 10, 11 is intended to cooperate with latch 7 when it is desired to maintain the door 3 locked by positive means rather than merely closed by magnetic attraction of parts 8 and 13. Latch 7 is arranged on door 3 in juxtaposition to passageway `17a defined by housing 10, 11 and enters into housing 10, 11 whenever door 3 is closed and then engages latch 16. Latch 16 forms an integral part'of a pivotable armature 15 under the action of an electromagnet 14 arranged inside housing 10, 11. The armature latch unit 15, 16 rests against a pair of abutments or stops 18 and 19.

FIG. 2 shows the electromagnet in de-energized conposition thereof. In the lower position of armature 15 latch 16 may engage latch 7 and thus maintain the cabinet door 3 locked. The pull exerted upon latch 16 by one who tries to forcibly -open locked cabinet door 3 is received by stop or abutment 19, and thus not transmitted to the fulcrum of armature 15 which is likely to be dam- J aged if subjected to such pull action. Upon energization of electromagnet or solenoid 14 armature 15 is lifted and latch 16 moved out of engagement with latch 7, thus making it possible to Iopen door 3 against the magnetic action of parts 13 and 8.

It `will be apparent from the foregoing that pant 3 performs two functions, i.e. it forms an armature cooperating with permanent magnet 17 to maintain door 3 closed by forces of magnetic attraction between these two parts, and it forms also a support for latch 7 cooperating with latch 16.

Referring now to FIGS. to 9, reference character L1 has been applied to generally indicate an assembly unit intended to be secured to a sliding door (not shown) Aand reference character L2' has been applied to generally indicate an assembly unit intended to be secured to a iixecl door frame 5 for the sliding door. Assembly unit L1 includes a housing made up of two complementary shells 11 which define a pair. of enclosed spaces 20' and 21. Housing 1G', 11', has a pair of parallel, relatively wide outer surfaces `of which one is its front surface shown in FIG. 6, and the other its rear surface. Housing 10', 11 further comprises a pair of relatively narrow lateral surfaces at right angles to the aforementioned pair of relatively wide surfaces. As best shown in FIG. 5 one of these relatively narrow surfaces defines a pair of superimposed passageways 17 and 17a. Passageway 17 arranged at a higher level than passageway 17a interconnects the space or compartment inside of housing 10', 11 with the exterior of said housing, and passage way 17a interconnects the space or compartment 21 inside' of housing 10, 11 with the outside of said housing. A pair of hollow rivets 12 project transversely through the relatively wide surfaces of housing 16', 11 and integrate its two constituent shells 10 and 11 into a structural unit. Each hollow rivet 12 defines a cylindrical duct for the passage of screws 6 intended to secure housing 10', 11' to a sliding door. These screws have been deleted in FIGS. 5 and 8. They are arranged in exactly the same fashion as the -wood screws 6 shown in FIGS. 2 and 4 and their cross-section is shown in FIGS. 6 and 9. Reference character 22 has been applied in FIG. 9 to indicate transverse passageways in each of shells 10 and 11 into which the aforementioned hollow rivets 12' are inserted. A permanent bar magnet 13 is arranged in space or compartment 20 of housing 10', 11. Bar -magnet 13 is provided with a coaxial stem 23 projecting into a recess 24 defined by shells 10 and 11. Mounted on stem 23 is a screw nut Z5 resting with one surface thereof against one of the lateral walls of recess 24. Rotation of screw nut 25 on screw-threaded stem 23 Lmakes it possibley to precisely position bar magnet 13 relative to housing 10', 11. As shown in FIG. 9 bar magnet 13 projects with the right end thereof into passageway 17 `and has a pole surface 13a arranged substantially ush 'with the narrow outer surface of housing 10', 11 shown to right of FIG. 9. Reference numeral 8' has ben applied to indicate a rectangular armature plate attracted by permanent bar magnet 13 and thus tending to oppose separation of units L1 and L2. Armature plate Sis arranged substantially parallel to the pole surface 13a of bar magnet 13. Armature plate `8' supports hooked latch 7 at a point thereof juxtaposed to, and arranged at the same level as, passageway 17a of housing 10', 11'. If housing 10', 11 is moved toward armature plate 8 the latch 7 thereof enters into passageway 17a and cooperates with a latch 16 inside housing 10', 11'. Latch 16 is piv-otally mounted on a pin 26 andunder the action of a helical over-center spring 27 of which one end is attached to latch'16 and the other end is attached to a fixed frame structure for an electromagnet 14. Pin 26' is supported by a U-shaped bracket 40' riveted to shell 10 at 28. Latch 16 denes a pair of recesses 29 and 30 each situated to opposite sides of the fulcrum of latch 16 formed by pin 26. Latch 16' has two limit positions of which one, i.e. the lower, is shown in FIG. 8, and which is characterized by the fact that the longitudinal axis of over-center spring 27 is situated below of pivot or fulcrum 26. If the front end, or right end, of latch 16 is lifted or pivoted in counterclockwise direction `against the action of spring 27', the longitudinal axis of spring 27 is moved across and past pivot or fulcrum 26', and then over-center spring 30 biases latch 26 in counterclockwise direction to the upper limit position thereof. As long as lat-ch 16 is in its lower limit position over-center spring 27 biases latch 16 in clockwise direction. The aforementioned electromagnet 14 is provided to move latch 16 selectively to each of its two aforementioned limit positions. To this end electromagnet 14 is provided with a klapper-type armature 15 pivoted at 31 and under the bias of a helical spring 32'. One end 33 of spring 32 is secured to housing 10', 11', while the other end 34 of spring 32 is secured to a substantially Z-shaped abutment 35 integral with armature 15. It is apparent from FIG. 9 that the space or cornpartment 21 of housing 10', 11, accommodates electromagnet 14', its armature 15, abutment 35 integral with the latter, latch 16 and the over-center spring 27 thereof. Compartment yor space 21 further accommodates a pair of terminal clamps 36 and 37 for connecting electromagnet 14 into an electric energizing circuit.

In FIG. 9 latch 16 has been shown in the latching position thereof, its cooperating latch 7' lhaving been indicated in that figure by a dash-and-dot line. In this position of latch 16 the units L1 and L2 cannot be separated, i.e. .the sliding door cannot be opened. Upon energization of electromagnet 14' armature 15 is pivoted about its pivot or ful-crum 31 in counterclockwire direction, as seen in FIG. 9. As a result, the upper end of abutment 35 engages recess 30 in latch 16 and pivots latch 16 in counter-clockwise direction to its upper limit position, or unlatched position (not shown). Now units L1 and L2 can readily be separated by overcoming the magnetic attraction between parts 13 and 8. The sliding door will, however, not open unintentionally upon movement of latch 16 to its upper limit position, or unlatched position, on account of the action of permanent magnet 13' and its armature 8. In the de-energized state of electromagnet 14' armature 15' rests against a stop 38 integral with `housing 10', 11'. Upon yre-energization of electromagnet 14 the abutment 35' of arma ture 15 engages the recess 29 in latch 16' and thus pivots latch 16 in clockwise direction as seen in FG. 9, thus moving latch 16' to its lower limit position, or latching position.

While there has been described what is at present considered to be the preferred embodiments of the invention, it will 'be obvious to those skilled in the art that various changes and modifications may be made without departing from the invention, and it is, therefore, aimed in the appended claims to cover all such changes and modifications as fall within the true spirit of the invention.

What is claimed is:

1. A latching mechanism for doors comprising in combination:

(a) a housing including a pair of complementary shells defining an enclosed space, said housing having a pair of juxtaposed wide surfaces and having a narrow surface defining a pair of superimposed passageways between said space and the outside thereof;

(rb) a permanent magnet inside said space projecting with one end thereof into one of said pair of passageways and having a pole surface arranged substantially flush with said narrow surface of said housing;u

(c) a latch pivotally mounted inside said space and pivotable to an operative position and to a non-operative position, said latch having a latching surface arrange-d substantially in registry with the other of said pair of passageways;

(d) an electromagnet inside said space including an armature for operating said latch; and

(e) a pair of hollow rivets projecting transversely through said juxtaposed surfaces of said housing and integrating said pair of shells into a structural unit, each of said pair of hollow rivets defining a cylindrical duct having a sufficiently large inner diameter t0 allow the passage of screws for supporting said housing through said juxtaposed surfaces of said housing.

2. A latching mechanism for doors comprising in combination:

(a) a housing including a pair of complementary shells defining an enclosed space, said housing having a pair of parallel relatively wide outer surfaces and having a pair of relatively narrow outer surfaces arranged at right angles to said pair of relatively wide outer surfaces, one of said pair of relatively narrow outer surfaces defining a pair of superimposed passageways between said space and `the outside thereof;

(b) a pair of hollow rivets projecting transversely through said pair of relatively wide outer surfaces of said housing andintegrating said pair of shells into a structural unit, each of said pair of hollow rivets defining a cylindrical duct having a sufficiently large inner diameter to allow the passage of screws for supporting said housing through said pair of relatively wide outer surfaces of said housing;

(c) a permanent magnet inside said space defined by said housing projecting with one end thereof into one of said pair of passageways and having a pole surface arranged substantially flush with ,said one of said pair of relatively narrow surfaces of said housme;

(d) a fixed armature plate cooperating with said permanent magnet to maintain a door by magnetic attraction in the closed position thereof, said armature plate being arranged substantially parallel to said pole surface of said permanent magnet;

(e) a first latch supported by said armature plate at a point juxtaposed to the other of said pair of passageways and projecting from said armature plate in the direction of said other of said pair of passageways;

(f) a second latch cooperating with said first latch and arranged inside said space and movable relative to said housing; and

(g) electromagnetic means inside said space for operating said second latch.

3. A latching mechanism for doors comprising in combination:

(a) a housing including a pair of complementary shells defining an enclosed space;

(b) a permanent magnet inside of said space having a pole surface arranged substantially flush with one side of said housing;

(c) a pivotable latch inside said space having a predetermined fulcrum and being pivotable to two limit positions about said fulcrum, said latch defining a pair of recesses each to one side of said fulcrum;

(d) an over-center spring biasing said latch to one of said two limit positions thereof; and

(e) an electromagnet inside said space including a pivotable armature having an abutment arranged to alternately engage uponany pivotal motion of said armature one of said pair of recesses defined by said latch to pivot said latch to one of said two limit positions thereof.

4. A latching mechanism for doors comprising in cornbin ation:

(a) a housing including a pair of complementary shells defining a pair of separate enclosed spaces; (b) a permanent magnet inside of one of said pair of' spaces having a pole surface arranged substantially ush with one side of said housing; (c) a fixed armature plate cooperating with said per- 6 manent magnet arranged substantially parallel to said pole surface thereof;

(d) a first latch supported by said armature plate and projecting from said armature plate;

(e) a second latch inside the other of said pair of spaces arranged to cooperate with said first latch, said second latch having a predetermined fulcrum, being pivotable about said fulcrum to two limit positions and defining a pair of recesses, each to one side of said fulcrum;

(f) an over-center spring inside said other of said pair of spaces biasing sai-d pivotable latch to one of said two limit positions thereof; and

(g) an electromagnet inside said other of said pair of spaces including a pivotable armature having an abutment arranged to alternately engage one of said pair of recesses defined by said second latch upon any pivotal motion of said armature to pivot said second latch to either one of said two limit positions thereof.

5. A latching mechanism for doors comprising in cornbination:

(a) a housing including a pair of complementary shells defining a pair of separate enclosed spaces, said housing having a pair of juxtaposed relatively wide outer surfaces and having a relatively narrow outer surface at right angles to said pair of relatively wide surfaces, said relatively narrow surface defining a pair of superimposed passageways each between one of said pair of enclosed spaces and the outside of said hous- (b) a permanent bar magnet inside of one of said pair of spaces projecting with one end thereof into one of said pair of passageways and having a pole surface arranged substantially iiush with said relatively narrow surface of said housing;

(c) a latch pivotally mounted inside the other of said pair of spaces and having a predetermined fulcrum, being pivotable about said fulcrum to two limit positions and defining a pair of recesses, each to one side of said fulcrum;

(d) an over-center spring inside said other of said pair of spaces ybiasing said latch to one of said two limit positions thereof;

(e) an electromagnet inside said other of said pair of: spaces including a pivotable armature having an abutment arranged to alternately engage one of said pair of recesses defined by said latch upon any pivotall motion of said armature to pivot said latch alternately to one of said two limit positions thereof; and

(f) a pair of hollow rivets projecting ltransversely through said juxtaposed surfaces of said housing integrating said pair of shells into a structural unit, each of said pair of hollow rivets defining a cylindrical duct having a sufficiently large inner diameter to allow the passage of a pair of screws for supporting said housing through said juxtaposed surfaces of said housing.

6. A latching mechanism for doors comprising in combination:

(a) a housing including a pair of complementary shells defining a pair of separate enclosed spaces, said housing having a pair of parallel relatively wide outer surfaces and a relatively narrow outer surface at right angles to said pair of relatively wide outer surfaces,

said relatively narrow outer surface defining a pair of superimposed passageways each between one of said pair of enclosed spaces and the outside of said housing;

(b) a pairY of hollow rivets projecting transversely through said relatively wide surfaces of said housing integra-ting said pair of shells into a structural unit, each of said pair of hollow rivets defining a cylindrical duct having a sufficiently large inner diameter 7 to allow the passage of a pair of screws for supporting said housing through said relatively wide outer surfaces of said housing; (c) a vpermanent bar magnet inside of one of said pair of said pair of passageways and projecting into said (c) a fixed armature plate cooperating with said bar magnet arranged substantially parallel to said one of said relatively narrow outer surfaces of said housing;

(d) a first latch supported by said armature plate at of spaces defined by said housing projecting with one substantially the sa-me level as the lower of said pair end thereof into one of said pair of passageways and of passageways and projecting from said armature having a pole surface arranged substantially ush plate in the direction of said -pair of passageways; with said relatively narrow outer surface of' Said (e) a second latch arranged inside said housing below housing; said bar magnet and cooperating with said rst latch, (d) a xed armature plate cooperating with said per- 10 said second latch having a predetermined fulcrum,

marient magnet and being arranged substantially parbeing pivotable to two limit positions about said fulallel to said pole surface thereof; Crum, and dening a pair of recesses each to one side (e) a rst latch supported by said armature plate at of said fulcrum;

a point juxtaposed to the other of said pair of pas- (f) an over-center spring inside said housing biasing sageways and projecting from said armature plate said second latch to one of said two limit positions in the direction of said other of said pair of passagethereof; and ways; (g) an electromagnet inside said housing, said electro- (f) a second latch cooperating with said fixed latch magnet including an energizing winding arranged at pivotally mounted inside the other of said pair of a point of said housing more remote from said one lspaces and pivotable to two limit positions thereof, of said pair of relatively narrow outer surfaces of said second latch having a predetermined fulcrum said housing than said bar magnet, said electroand dening a pair of recesses each to one side of magnet further including a pivotable armature said fulcrum; p arranged at a lower level than said energizing wind- (g) an over-center spring inside said other of said pair ing and having an abutment arranged to alternately of spaces lbiasing said movable latch to one of said engage one of said pair of recesses defined by said two limit positions thereof; and secon-d latch upon any pivotal motion of said arma- (h) an electromagnet inside said other of said pair of ture under the action of said energizing winding to spaces including a pivotable armature having an pivot said second latch alternately to one of said two abutment 4arranged to alternately engage one of said limit positions thereof. pair of recesses defined by said second latch upon any pivotal motion of said armature to pivot said Refeences Cited by the Examiner second latch alternately to one of said two limit posi- UNITED ST ATES PATENTS P 7 triitizhihevoiechanism for doors comprising in com- 526323 9/1894 Magovem et al' bmtion, D 971,423 9/1910` Walters 292-201 (a) a-housing including a pair of complementary shells 1301789 www Howard et al' d h 'l' f relativ 1 Wide Outer Surfaces Peltier n X and havlng a Pil E l le Y f 2,494,672 i/io schonen 292-122 X an aving a pair o re ative y narrow outer sur aces 2,840,405 6/1958 Feltz et al. 292 122 at right angles to said pair of relatively wide outer 3 111 020 11/1963 G c.' f relativel narrow outer 40 arma 7o- 107 Surfaces one. d Pa 0 Y 3,201,960 8/1965 Berkowitz 292-126 X surfaces defining a pair of superimposed passageways between the interior of said housing and the exterior FOREIGN PATENTS thereof; l 1,298,999 6/1962 France. (b) a permanent bar magnet inside said housing 1,072,926 1/196() Germany arranged at substantially the same level as the upper 4 685,404 1/1953 Great Britain.

upper of said pair of passageways and having a pole surface substantially flush with one of said relatively narrow surfaces of said housing;

MARVIN A. CHAMPION, Primary Examiner,

RICHARD E. MOORE, Examiner. 

4. A LATCHING MECHANISM FOR DOORS COMPRISING IN COMBINATION: (A) A HOUSING INCLUDING A PAIR OF COMPLEMENTARY SHELLS DEFINING A PAIR OF SEPARATE ENCLOSED SPACES; (B) A PERMANENT MAGNET INSIDE OF ONE OF SAID PAIR OF SPACES HAVING A POLE SURFACE ARRANGED SUBSTANTIALLY FLUSH WITH ONE SIDE OF SAID HOUSING; (C) A FIXED ARMATURE PLATE COOPERATING WITH SAID PERMANENT MAGNET ARRANGED SUBSTANTIALLY PARALLEL TO SAID POLE SURFACE THEREOF; (D) A FIRST LATCH SUPPORTED BY SAID ARMATURE PLATE AND PROJECTING FROM SAID ARMATURE PLATE; (E) A SECOND LATCH INSIDE THE OTHER OF SAID PAIR OF SPACES ARRANGED TO COOPERATE WITH SAID FIRST LATCH, SAID SECOND LATCH HAVING A PREDETERMINED FULCRUM, BEING PIVOTABLE ABOUT SAID FULCRUM TO TWO LIMIT POSITIONS AND DEFINING A PAIR OF RECESSES, EACH TO ONE SIDE OF SAID FULCRUM; (F) AN OVER-CENTER SPRING INSIDE SAID OTHER OF SAID PAIR OF SPACES BIASING SAID PIVOTABLE LATCH TO ONE OF SAID TWO LIMIT POSITIONS THEREOF; AND 